The Donnay customization kit that is sold separately allows users the option to adjust the weights and balances exactly to their liking to any Donnay racquet. There are three interchangeable buttcaps weighing two, seven and 12 grams, along with weighted slides that can be easily applied to the sides and top of the frame in the blink of a changeover. The combination of the slides and lightest buttcap tips the balance more to the head for more power; no slides and the heaviest buttcap increase control and further enhance maneuverability. There are 10 combinations in between.